Abstract: When a current landscape includes an upward slope and a downward slope existing ahead of the upward slope, a controller determines a virtual design surface including a first design surface inclined at a smaller angle than the upward slope and a second design surface inclined with respect to the first design surface at a smaller angle than the downward slope. The controller generates a command signal that causes a work implement to move along the virtual design surface.

Abstract: A work vehicle control system includes an actual topography acquisition device, a storage device, and a controller. The actual topography acquisition device acquires actual topography information, which indicates an actual topography of a work target. The storage device stores design topography information, which indicates a final design topography that is a target topography of the work target. The controller acquires the actual topography information from the actual topography acquisition device. The controller acquires the design topography information from the storage device. When the actual topography positioned below the final design topography is sloped, the controller generates a command signal to move the work implement along a locus positioned below the final design topography and below the actual topography, and a sloped locus that is positioned below the final design topography and above the actual topography.

Abstract: A controller acquires an excavation start position at which a work implement starts excavation. When a current landscape includes an upward slope and a downward slope existing ahead of the upward slope and the excavation start position is on the upward slope, the controller determines a first virtual design surface including a first design surface located below the current landscape and inclined at a smaller angle than the upward slope. The controller generates a command signal that causes the work implement to move along the first virtual design surface.

Abstract: A work vehicle control system includes an actual topography acquisition device, a storage device, and a controller. The actual topography acquisition device acquires actual topography information, which indicates an actual topography of a work target. The storage device stores design topography information, which indicates a final design topography that is a target topography of the work target. The controller acquires the actual topography information from the actual topography acquisition device. The controller acquires the design topography information from the storage device. The controller generates a command signal to move the work implement along a locus that is more gently sloped than the actual topography when the actual topography positioned below the final design topography is sloped.

Abstract: A bulldozer includes a blade pivotably attached to a vehicle body, a blade operation lever, and a blade control section. The blade operation lever outputs a lowering instruction signal, a holding instruction signal, and a raising instruction signal for the blade. The blade control section controls a height of the blade according the signal input. The blade control section can lower the blade to a predetermined position when the lowering instruction signal and the holding instruction signal are input in order after a transmission has been switched from a state, which is different from an advancing state, to the advancing state. The blade control section can raise the blade to a predetermined position when the raising instruction signal and the holding instruction signal are input in order after a transmission has been switched from a state, which is different from a reversing state, to the reversing state.

Abstract: A bulldozer includes a blade pivotably attached to a vehicle body, a blade operation lever, and a blade control section. The blade operation lever outputs a lowering instruction signal, a holding instruction signal, and a raising instruction signal for the blade. The blade control section controls a height of the blade according the signal input. The blade control section can lower the blade to a predetermined position when the lowering instruction signal and the holding instruction signal are input in order after a transmission has been switched from a state, which is different from an advancing state, to the advancing state. The blade control section can raise the blade to a predetermined position when the raising instruction signal and the holding instruction signal are input in order after a transmission has been switched from a state, which is different from a reversing state, to the reversing state.